Hello,

I'm implementing visual scripting similar to what Unreal realizes in their blueprints to my engine. Now I'm wondering, how do you render those kind of connection-splines in DX/OpenGL?

As you can see in this screenshot, they behave quite... special... and appear totally smooth here. I suppose that did use something other than pure DX/OGL, but does somebody know a formular for generating enough controller-points between two points p1 and p2 so I can render such a smooth line in that fashion using line rendering?

I suspect you'll be able to draw such a spline as a Hermite curve using only an outgoing and an incoming set of positions and (flat/horizontal) tangents.

You can use the Hermite routines that come with the D3DX-library.

http://msdn.microsoft.com/en-us/library/windows/desktop/bb204998(v=vs.85).aspx

Or you can use the cubic equations mentioned there directly.

Thanks,

I managed to get a generic b-spline algorithmn that I further found to running using the control points you mentioned, though I had to use delta-x/2 to get the desired result. I'm simply drawing the lines in DX/GL for now, since my whole gui is rendered with those, it fit better than using GDI. Now all I've got to do is adding support for drawing thicker lines, but I already got an basic idea how to do this, so not a problem.